Famicom AV w/ tim NESRGB Audio Buzz

[CesarDRK]

Hi guys, i recently had my Famicom AV (HVC-101) modded for RGB using the latest TIM RGB board by a local modder.
Before that i was using composite with the retrotink 2x.

He did a full cleaning + recap + rgb mod (set to improved, without the switch attached). Now im using it with the OSSC @ line 5x in my 55" c9 oled.
The problem is now in some games i hear an annoying buzz in my soundbar.
Some examples (always using Krikz EDN8):
- Akumajou Densetsu (JP) = very annoying buzz, easily audible when in silence or paused.
- Super Mario Bros 3 (JP or USA) = very annoying buzz, easily audible when in silence or paused.
- Rockman 5 (JP) = unnoticeable.
- Friday the 13th (US) = unnoticeable.
- Chip and Dale Rescue Rangers (US) = unnoticeable.

Before the mod i have only tested the SPM3 (the only real cart i have atm), which from what i recall didnt have any noticeable buzzing.
I got the EDN8 after the mod. Im using a shielded RGB C-SYNC scart cable (the same cable that i use with the N64 and my SNES 1-chip without any issues).

He says that there´s no issue with the console or mod itself, but i find this extremely annoying.
Is there any hope to fix this issue??

Here are some pics, and an audio clip recorded with my PHONE near the sounbar:

https://soundcloud.com/user-878099407/n ... zing-issue

https://pasteboard.co/IWBT0cB.jpg
https://pasteboard.co/IWBTbRM.jpg
https://pasteboard.co/IWBSKvB.jpg
https://pasteboard.co/IWBTjgj.jpg
https://pasteboard.co/IWBTpzS.jpg

[daskrabs]

Your modder didn't utilize the NESRGB's on-board sound amp. Have him/her change it. It sounds way better than the stock amp and would almost certainly eliminate any residual buzz.

[thebigcheese]

Out of curiosity, where did you get the cable from? As long as the audio is shielded separately from everything else, you should be fine. But I found the NES to be extra susceptible to buzz and had to use a fully shielded coax cable from Retro Access to get rid of the buzz. Packapunch from RGC should work fine as well.

[thebigcheese]

Your modder didn't utilize the NESRGB's on-board sound amp. Have him/her change it. It sounds way better than the stock amp and would almost certainly eliminate any residual buzz.

The standard procedure (provided by Tim, anyway) doesn't reroute the audio for the Famicom AV. Looking it over now, it occurs to me that I might also benefit from using it with the toploader I have. Do you happen to have info on how this ought to be connected for either of those systems?

[CesarDRK]

Your modder didn't utilize the NESRGB's on-board sound amp. Have him/her change it. It sounds way better than the stock amp and would almost certainly eliminate any residual buzz.

In tims guide for the AV famicom this is not even mentioned. From what ive seen this is recomendded for non AV models.
Have you tried this in an AV model?

Out of curiosity, where did you get the cable from? As long as the audio is shielded separately from everything else, you should be fine. But I found the NES to be extra susceptible to buzz and had to use a fully shielded coax cable from Retro Access to get rid of the buzz. Packapunch from RGC should work fine as well.

I got the cable from directly from him, he builds then in his shop.

[Kez]

I would expect it to be either the cable or the PSU. What PSU are you using? Do you have any others you can try? NTSC SNES or Genesis Model 1 for example should work.

To investigate the cable, you can try loading up 240p test suite and putting up a bunch of different patterns. If the noise is coming from video interference, you will notice that some patterns (e.g. checkerboard or solid white screen) will produce a lot more noise than others.

[CesarDRK]

I would expect it to be either the cable or the PSU. What PSU are you using? Do you have any others you can try? NTSC SNES or Genesis Model 1 for example should work.

To investigate the cable, you can try loading up 240p test suite and putting up a bunch of different patterns. If the noise is coming from video interference, you will notice that some patterns (e.g. checkerboard or solid white screen) will produce a lot more noise than others.

I have three original SNES psu's, but the connector doesnt fit unfortunately.
The Genesis PSU works, but mine is generic. It produces the same results.

Actually i tried the 240p test suite. In some tests i did noticed that the interference is louder (checkerboard from what i recall).
Does this means my cable isnt good enough?

[thebigcheese]

Looking at the cables Tim sells, I'm guessing they use an overall shield and not individual shielding, so it's probably the cable. Order one from Retro Access or a packapunch cable from Retro Gaming Cables and that should get rid of the buzz.

[ChuChu Flamingo]

Famicom/NES is well known to be prone to buzzing due to the large use of solid colors. For that reason alone it will show buzzing with ease vs other consoles if you don't have a fully shielded cable.

[Kez]

Actually i tried the 240p test suite. In some tests i did noticed that the interference is louder (checkerboard from what i recall).
Does this means my cable isnt good enough?

It's a strong indication. You could always pop the SCART cable open and take a picture of the wires.

[CesarDRK]

Looking at the cables Tim sells, I'm guessing they use an overall shield and not individual shielding, so it's probably the cable. Order one from Retro Access or a packapunch cable from Retro Gaming Cables and that should get rid of the buzz.

Famicom/NES is well known to be prone to buzzing due to the large use of solid colors. For that reason alone it will show buzzing with ease vs other consoles if you don't have a fully shielded cable.

It's a strong indication. You could always pop the SCART cable open and take a picture of the wires.

This is the cable i´m using. It appears not to be individually shielded.

https://pasteboard.co/IWGN66f.jpg
https://pasteboard.co/IWGNJYp.jpg

Just ran 240p test suite again and there is a huge buzz when displaying the grid and scrolling grid options.

[matt]

In tims guide for the AV famicom this is not even mentioned. From what ive seen this is recomendded for non AV models.
Have you tried this in an AV model?

I did this on my AV Famicom. When I first modded it, I left the stock audio in place and had the exact same problem - lots of buzzing with certain display patterns that wasn't there prior to the mod. It sounded awful. Routing the audio through the NESRGB's onboard sound amp fixed the problem, and now it sounds better than it did before the RGB mod.

In your pics of the mod, only the RGB is hooked up. Have your modder change the audio and you should be fine.

I don't think changing your AV cable will help. Your cable isn't individually shielded, but it's high enough quality that it wouldn't cause the level of interference that you're describing.

[CesarDRK]

In tims guide for the AV famicom this is not even mentioned. From what ive seen this is recomendded for non AV models.
Have you tried this in an AV model?

I did this on my AV Famicom. When I first modded it, I left the stock audio in place and had the exact same problem - lots of buzzing with certain display patterns that wasn't there prior to the mod. It sounded awful. Routing the audio through the NESRGB's onboard sound amp fixed the problem, and now it sounds better than it did before the RGB mod.

In your pics of the mod, only the RGB is hooked up. Have your modder change the audio and you should be fine.

I don't think changing your AV cable will help. Your cable isn't individually shielded, but it's high enough quality that it wouldn't cause the level of interference that you're describing.

I asked him about and he said this would be a destructive operation, having to disable the original circuit (cutting traces and such) to re-route to tim's board.
Have you done it yourself? What is the procedure?

[thebigcheese]

I am about to do it this weekend, though this will be on a toploader NES (which does not really have any onboard audio circuit). From what I can tell, you just wire up CPU pins 1 and 2 to the NESRGB, then wire the NESRGB to the audio out on the multiout. In my case, there's nothing destructive about it. If it comes to it, I could lift those CPU pins to get them out of the circuit, but that can be done nondestructively. I suspect that could also be done on the AV Famicom, but you might have to cut the trace for the audio out on the multiout. Honestly, I would just order a new cable and see how that goes. Individual shielding made all the difference for me. TONS of buzz without it, even with a quality cable that works with all my other systems, and no buzz at all with it. I'm only rerouting the audio because I suspect I'll get a little more volume out of it since there's no onboard amplification on the toploader (outside of the RF modulator, which I removed).

[matt]

I asked him about and he said this would be a destructive operation, having to disable the original circuit (cutting traces and such) to re-route to tim's board.
Have you done it yourself? What is the procedure?

Yes, you have to cut some traces, but it's pretty simple and easy to do. As a whole it's still less destructive than the rest of the NESRGB mod and you could reverse it if needed. The results are good enough that you wouldn't want to go back.

[CesarDRK]

Honestly, I would just order a new cable and see how that goes. Individual shielding made all the difference for me. TONS of buzz without it, even with a quality cable that works with all my other systems, and no buzz at all with it.

I think im going to go this route, but im not sure what cable to get honestly. I see there´s two options for the packapunch SNES Csync cable, either passtrough or 470ohm and also two options for the retro access SNES csync TTL or 330 ohm.

[Link83]

Honestly, I would just order a new cable and see how that goes. Individual shielding made all the difference for me. TONS of buzz without it, even with a quality cable that works with all my other systems, and no buzz at all with it.

I think im going to go this route, but im not sure what cable to get honestly. I see there´s two options for the packapunch SNES Csync cable, either passtrough or 470ohm and also two options for the retro access SNES csync TTL or 330 ohm.

That really depends on how the J8 jumper has been configured on your NESRGB board:-
http://etim.net.au/nesrgb/NESRGB-Pinout.pdf
If its configured for 75ohm CSYNC then you want a straight through cable.
If its configured for TTL CSYNC then you want a cable with a 330-470ohm resistor.

[CesarDRK]

That really depends on how the J8 jumper has been configured on your NESRGB board:-
http://etim.net.au/nesrgb/NESRGB-Pinout.pdf
If its configured for 75ohm CSYNC then you want a straight through cable.
If its configured for TTL CSYNC then you want a cable with a 330-470ohm resistor.

Thanks. It´s open, so 330-470ohm it is.

Now one more choice.. Retro access COAX vs FORTRAFLEX vs Pakapunch..

[PaTaito]

Sorry to revive an old thread. I have just purchased an AV Famicom with tim's NESRGB V4.0 installed, along with the audio balance resoration mod(from retroupgrades in the UK). I get the same exact buzzing on the audio out both with my authentic akumajou densetsu cart, and my everdrive N8 pro too. The N8 pro is ever so slightly more noisy...just a hair.

The weird thing is, it stops when I disconnect my retro-bit n30 controller receiver, OR when i place my hand near the controller port, meaning its surely some kind of ground issue right? I'm using a triad psu, and shielded SNES RGB cables.

Any help/imput would be greatly appreciated.

[Icelvlan]

I’m having the same issue. I notice I can reduce it is I just slightly use turn on the system with the power switch.